Roll blasting equipment



March 25, 1952 R. B. HUYETT ROLL BLASTING EQUIPMENT 2 SHEETSSHEET 1 Filed July 8, 1949 I N VEN TOR.

B- Hl/YEm March 25, 1952 R. B. HUYETT 2,590,819

ROLL BLASTING EQUIPMENT Filed July 8, 1949 2 SHEET8--SHEET 2 Patented Mar. 25, 1952 ROLL BLASTING EQUIPMENT Robert B. Huyett, Hagerstown, Md., assignor to Pangborn Corporation, Hagerstown, Md., a corporation of Maryland Application July 8, 1949, Serial No. 103,710

5 Claims.

To produce sheets of uniform thickness and finish, the contact surface of rolls must have substantially a straight line contact and the matte surface produced by blasting must be uniform.

The present invention provides a machine for obtaining such uniformity in the blasting of such roll surfaces, and especially a machine in which the blast projector is traversed longitudinally relative to the roll while the roll is rotated in such a manner as to maintain a fixed predetermined relation between the roll-rotating speed and the speed of relative traverse of the work and blast projector. The maintenance of such fixed ratio during the blasting of a roll insures the production of a uniform blast finish of the entire peripheral surface of the roll.

Without changing the predetermined ratio be.- tween the speed of traverse and the rate of roll rotation in revolutions per minute, with the new machine predetermined blasting of the roll surface irrespective of the roll diameter may be effected by varying the driving speed of the common rotating and traversing mechanism. By altering the ratio between the driving and rotating mechanism, any desired type of blast finish may be effected.

Thus by the presentv invention the particular roll surface desired may be attained while all tendency to locally depart from the uniformity of blasting desired is avoided.

Particular objects and advantages of the, invention will be apparent from the following description of a preferred embodiment thereof. The invention resides in the novel arrangements and combinations of parts hereinafter set forth and claimed.

In the accompanying drawings:

Fig. 1 is a diagrammatic plan view of an exemplary roll blasting machine embodying the invention, various conventional parts being omitted for clarity; 1

Fig. 2 is a diagrammatic partial side elevation thereof;

Figs. 3 is a diagrammatic partial end elevation thereof; and

Fig. 4 is a diagram of a preferred form of carriage drive reversing mechanism employable in such embodiment.

In the embodiment shown in the drawings, the machine comprises a housing I of elongated form having doors 2 at one of its ends and provided with a trackway 3, on which a car 4 may be moved into and out of the housing. The car 4 in the form shown is provided with means for rotatably supporting the roll to be blasted with its axis horizontally disposed and parallel to the longitudinal axis of the housing. In the form shown the roll 5 (which may be, say, two feet in diameter and of an overall length of ten feet or more, with a cylindrical working surface four-feet or more in length) has its ends 6 supported in adapters l, which in turn are rotatably mounted on free rollers 8 carried by the car 4.

One of the adapters 1, herein that which enters the housing first, is provided with rotating coupling means 9 engaging with a rotating spindle I0 which projects into the housing I through the wall thereof opposite the doors, and coaxial with the axis of the roll and its mounting adapters.

In this way, by merely entering the roll on its carriage into the housing so that its special adapter B9 engages the spindle, rotation of the spindle effects a positive rotation of the roll at a rate corresponding in revolutions per minute to the rate of rotation of the spindle.

Suitable means is provided for driving the spindle, herein comprising the speed reducer I l having its output connected to the spindle by chainand-sprocket drive l2 and receiving its input from a variable speed driving unit, herein shown. as the variable speed motor l3.

Suitably associated with the housing, and herein carried by one of the side walls thereof, is a longitudinally traversable blast projector l4 shown as of the blast nozzle type, though other forms of projector, for example the centrifugal type, may be employed. In the form shown the blast projector M is carried by a traversing plate l5 mounted to move parallel to the axis of the roll 5 on longitudinal rail members [6, suitable anti-friction rollers ll bein preferably included in this mounting. Extending parallel to the traversing rails I6 is a traversing belt 18 herein shown as mounted exteriorly of the housing and connected to the nozzle and plate assembly in any suitable manner.

Means is provided for driving the traversing belt infixedratio to the rate of rotation of the 3 spindle l0, which means in the form shown comprises a countershaft l9 connected by chain-andsprocket drive 20 with the shaft of spindle l and extending through a shifting-clutch type of reversing gear 2| to a suitable speed reducer 22.

Where a predetermined fixed ratio of speeds is to be permanently employed the speed reducer 22 preferably is of the worm-and-wheel type. Where it is desired to provide for changing the ratio between operations of the machine to change the pitch of the spiral blasting for different purposes, shift-gearsor any other variable speed type of speed reducer 22 may be employed. The output shaft 23 of speed reducer 22 in the form shown is connected to drive the traversing belt 58.

In the embodiment shown, means is also provided for effecting automatic reversal of the traversing drive. In the exemplary embodiment this means is electro-pneumatic in character. In this form the shift lever 24 of the reversin gear '2l is actuated by a double-acting pneumatic cylinder 25, the control valve 26 of which is controlled by double-acting solenoid means 21 suitably energized as from power source 28 diagrammatically shown as a transformer, and selectively controlled by limit switches 29 and 30, shown arranged adjacent to the limits of traverse of the nozzle carriage l and as tripped respectively by dogs, spring-pressing members or like tripping means 3| and 32 as the blast projector reaches the respective end of its traverse.

In the arrangement shown the valve 26 is of the balanced plunger type and admits compressed air from line 26a to the space between the plunger heads which communicates with one end or the other of the double-acting pneumatic cylinder 25 depending on the position of the valve plunger. As is diagrammatically shown the end of the cylinder which is not connected to the high-pressure source 26a may simply vent to atmosphere as through the outer end of the valve housing 26.

Any appropriate means may be provided for supplying the blasting grit to the blast projector so as to obtain a uniform stream of the desired intensity. When a pneumatic blast nozzle is employed such as that shown for purposes of illustration, this means may take the form of a double-chamber abradant pressure tank 33 (Fig. 1) connected in any suitable way, as by the hose line 34, to deliver abradant and high-pressure propelling fluid to the nozzle or blast projector 14. The abrasive line may be suspended above the traversing nozzle or be otherwise arranged in any known or convenient manner.

In the usual installation the housing I0 is supplied with grit elevating means 35 (Fig. 1) and 'with a grating or like perforated floor overlying an underlying grit-collecting hopper, ventilating means, and grit separating and reclaiming means,

all of which may be of conventional form and hence are not shown in the drawings.

From the foregoing description it will be seen that with the present machine a fixed relationship between the rate of angular rotation of the roll and the rate of traverse of the blast projector is predetermined to afford a uniform spiral blasting of the roll in either direction, with the desired amout of overlap for producing the desired unimay be altered whil maintaining the aforesaid ratio. Thus blasting per unit of roll surface, effected in each traverse of the nozzle, may be maintained substantially uniform despite variations in roll diameter and surface area.

It will be apparent that by the features of this invention a simple'and effective machine is provided for blasting of rolls with a high degree of uniformity. It is to be understood that the specific embodiment herein disclosed is illustrative and not restrictive of the invention, the scope of the invention being defined in the appended claims, and that all modifications which come within the meaning or the range of equivalency of the claims are therefore intended to be included therein.

I claim as my invention:

1. In a blasting machine for blasting with abrasive particles the outer surface of an elongated metal roll to give this surface a highly uniform matte finish: rotatable roll-supporting elements journalled for rotatably supporting a roll to be blasted; said elements being mounted for translational movement to carry a roll supported on these elements along a predetermined path; driving structure including roll-rotating mechanism having coupling elements mounted for rotation at a substantially fixed position to automatically come into driving engagement with a roll supported by the support elements as these elements are moved toward this position; and abrasive particle projecting structure; said driving structure including traversing mechanism connected for carrying the abrasive particle projecting structure longitudinally of the roller supported by the supporting elements at a rate which has a predetermined fixed relation to the roll rotation rate to provide a uniform overlapping of the blast swath and causing projected abrasive particles to uniformly abrade the external roll surface as the roll is rotated.

2. The combination as defined by claim 1 in which the said traversing mechanism includes a belt wound on and extending between pulleys fastened adjacent the respective ends of the traverse path, the abrasive particle projecting structure is connected to the belt for movement along the traverse path in response to movement of the belt, and the belt is connected for auto matic reciprocating movement to and fro between the rollers.

3. The combination defined by claim 1 in which the abrasive particle projecting structure includes a grit-blasting nozzle, the driving structure has an adjustable roll-driving speed to compensate for the difference in diameter of different rolls to be blasted, and the traversing mechanism includes an automatically-reciprocating adjustable drive ratio for moving the nozzle to and fro longitudinally of the roll to be blasted at a selectable fixed speed with respect to the roll rotation.

4. In a blasting machine for blasting with small particles the outer surface of an elongated article: driving structure mounted for rotating the article to be blasted about its longitudinal axis; and particle projecting structure; said driving structure including traversing mecha nism connected for carrying the particle projecting structure longitudinally of the rotating article, said traversing mechanism including a belt wound on and extending between pulleys fastened adjacent the respective ends of the traverse path, the particle projecting structure being connected to the belt for movement along the traverse path in response to movement of the belt, and the belt is connected for automatic reciprocating movement to and fro between the pulleys.

5. The combination defined by claim 4 in which the driving structure includes support elements for rotatably supporting the article to be blasted, and a housing envelop. the article to be blasted, the support elements, and the particle projecting structure; the remainder of the driving structure being outside the housing, and said housing has walls with a first opening for the penetration of a rotating driving member for transmitting rotation to the rotatably supported article from the outside of the housing to the inside, and a second opening for the penetration of the particle projecting structure, said second opening being covered by the belt.

ROBERT B; HUYE'IT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 349,544 Warrington Sept. 21, 1886 445,197 Phillips Jan. 27, 1891 1,476,854 'Iilley Dec. 11, 1923 1,836,941 Spicer Dec. 15, 1931 1,912,760 Coherly et a] June 6, 1933 2,247,479 Caldwell July 1, 1941 2,268,028 Fairbairn Dec. 30, 1941 2,495,269 Lindma-rk Jan. 24, 1950 

